Wildhorn

Dry avalanches in high Alpine regions. Wet avalanches as the day progresses.

The fresh snow of the last two days as well as the sometimes large wind slabs can be released by a single winter sport participant in some cases at elevated altitudes. In particular on very steep north facing slopes avalanches can be released in deep layers of the snowpack and reach large size in isolated cases. Caution is to be exercised in particular in areas where the snow cover is rather shallow. Ski touring calls for experience in the assessment of avalanche danger. The Avalanche Warning Service currently has only a small amount of information that has been collected in the field, so that the avalanche danger should be investigated especially thoroughly in the relevant locality.

Snowpack Sometimes large snow drift accumulations have formed in particular on the main Alpine ridge in Valais. In all regions at elevated altitudes, fresh snow and snow drift accumulations remain prone to triggering in some instances. They are lying on a moist old snowpack which, in southern Valais, on the southern flank of the Alps and in Grisons on north facing slopes, is weak in some cases. Under the influence of strong solar radiation and warming, natural avalanches are to be expected from as early as the morning. In particular on north facing slopes above approximately 2400 m, avalanches can release the entire snowpack in some cases. Large avalanches are possible. Observed weather review Tuesday, 02.05.2023 During the night the precipitation ceased in the west at first and then in the early morning in Grisons as well. The snowfall level dropped to approximately 1800 m. In southern Valais there were bright spells during the second half of the night. During the day it was partly sunny in the west and south, otherwise very cloudy. Fresh snow From midday on Monday until the precipitation ceased on Tuesday morning, the following amounts of snow fell above 2500 m:

• Northern Grisons, Engadine: 15 to 25 cm
• Elsewhere: up to 15 cm

Since Sunday morning the following aggregate amounts of snow have therefore fallen above approximately 2800 m:

• Southern Valais, western Ticino: 40 to 60 cm
• Northern flank of the Alps west of the Reuss, other regions of Valais, of Ticino and of the main Alpine ridge, Engadine: 25 to 40 cm
• Elsewhere: approximately 15 to 25 cm

Temperature At midday at 2000 m: between +1 °C in the north and +6 °C in the south Wind Light to moderate, but locally strong on the main Alpine ridge, from the north Weather forecast through Wednesday, 03.05.2023 The night skies will be clear in the far west, in Valais and in the south. In the other regions the cloud will disperse during the first half of the night, but in Grisons not until the second half of the night. During the day it will be sunny and become much warmer from the west. Fresh snow - Temperature

• At midday at 2000 m: between +9 °C in Valais and +5 °C in the east
• The zero degree level will rise to 3400 m in the west and to 3000 m in the east

Wind

• On Tuesday evening on the main Alpine ridge and to the south, moderate to locally strong from the north
• Otherwise, light to moderate from the northeast

Outlook through Friday, 05.05.2023 On Thursday, after a clear night and with the zero degree level at 3500 m, it will be very warm. On Friday, after a mostly clear night, it will be partly sunny on the northern flank of the Alps and a little precipitation may fall. In the other regions it will be mostly sunny. Even though the zero degree level will drop to 3000 m, it will remain very mild. On each of the coming days the wind will be mostly light. The danger of dry avalanches will decrease. In the early morning on each day, the conditions for backcountry touring will be quite favourable for a while. In particular on very steep north facing slopes between approximately 2400 and 3000 m, however, even if the surface of the snowpack is frozen, people can still trigger isolated avalanches, especially in Grisons. On each of the coming days, the danger of wet snow avalanches will increase quickly and markedly as the day progresses. Backcountry touring and ascents to refuges are to be concluded very early.